Fluxes

 

ChirpyToday at 6:11 PM

hi

[6:13 PM]

the salt works because the salt is really agressive to oxides when molten, thats why if you use a salt flux in pottery and try firing it, it'll just tear the lining apart and eat it to no end, which alot of those bricks are made of aluminum oxide(edited)

[6:14 PM]

the 50/50 mix works because sodium chloride melts at 1450F, potassium chloride melts at 1500F, but when they melt together, they form an eutectic which melts at around 1000F

[6:15 PM]

there are different salts that you can add to that mix to drop it even lower, which is handy for dropping it down to the temp that zinc alloys can use

[6:15 PM]

@Dusty Dan @Helpful Hardware Professor

[6:15 PM]

and no need to add anything else to the flux tbh for aluminum, those two work perfectly fine

Paul JoatToday at 6:16 PM

So do you melt the salt together before using it as flux then?

ChirpyToday at 6:16 PM

when they're really fine like you find in the containers of morton's lite salt, the grains are close enough together and well mixed enough that it can react with each other when it's in contact with the metal

Shims from common materials.

One can find many sources for stock 4 thou and up.  Paper, card stock etc.

For thinner I am trying aluminum foil.

• Reynolds Pitmaster is 1.6 thou
• Reynolds Heavy Duty is 1.0 thou
• Regular foil is about .3 thou

That should about cover it

Together the Pitmaster and Heavy Duty run about $10 at my local grocery store, quite a bargain given that you still have the bulk of the foil to use in the kitchen.

I have seen pitmaster online for as much as $18.  Don't go there.

Update:

Made a hole punch on the lathe for punching the centers.   Started with round stock from rebar that was .450.    Drilled a .shallow 404 hole, desired hole size,  and through drilled a bit larger than 1/4" The flaw here is that my punched holes are .450 not .404.    Need to start with a .404 stock and drill a  .350 or so hole to get a .404 hole.  But these are clearance holes in aluminum foil so I don't see a problem.

It needs to be a shallow hole because wall thickness is .046/2 or .023.  Maybe one could use a smaller drill and sharpen after turning.  I am using this on the way it came off the lathe.   Position the foil on a block of wood and  run the punch a bit into the wood.  I folded six layers and punched them.  Was a bit much 4 might be better.   The outside edges can be trimmed after the bearing cap is tight.  

If I had drilled the .404 hole and sharpened from the outside the hole size would have be closer if not correct.  But when I got going I could see that the wall after drilling was thin enough that I did not need to sharpen it.

If I needed to punch leather or vinyl I might temper and sharpen the punch but its not needed here.

 

Update Nov 24 2021

Had the Atlas  10F spindle off to fix the thrust bearing so I had to reshim the bearings again.
Turned a new punch because I could not find the old one.  Used larger stock and put the taper on the outside as suggested above.  Made the hole a bit larger so foil does not run on the bolts.

The foil is a bit hard to manage.  Used elmer's spray adhesive to glue two sheets of pitmaster foil for shims that were about 3 thou.   These are much easier to handle.  I think I used 6 thou of shims on one side and 7 on the other front and back.